b7e04f8c61
move watchdog tree from drivers/char/watchdog to drivers/watchdog. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
269 lines
6.4 KiB
C
269 lines
6.4 KiB
C
/* drivers/char/watchdog/scx200_wdt.c
|
|
|
|
National Semiconductor SCx200 Watchdog support
|
|
|
|
Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
|
|
|
|
Some code taken from:
|
|
National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
|
|
(c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>
|
|
|
|
This program is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU General Public License as
|
|
published by the Free Software Foundation; either version 2 of the
|
|
License, or (at your option) any later version.
|
|
|
|
The author(s) of this software shall not be held liable for damages
|
|
of any nature resulting due to the use of this software. This
|
|
software is provided AS-IS with no warranties. */
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/init.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/scx200.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
#include <asm/io.h>
|
|
|
|
#define NAME "scx200_wdt"
|
|
|
|
MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
|
|
MODULE_DESCRIPTION("NatSemi SCx200 Watchdog Driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
|
|
|
static int margin = 60; /* in seconds */
|
|
module_param(margin, int, 0);
|
|
MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
|
|
|
|
static int nowayout = WATCHDOG_NOWAYOUT;
|
|
module_param(nowayout, int, 0);
|
|
MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
|
|
|
|
static u16 wdto_restart;
|
|
static struct semaphore open_semaphore;
|
|
static char expect_close;
|
|
|
|
/* Bits of the WDCNFG register */
|
|
#define W_ENABLE 0x00fa /* Enable watchdog */
|
|
#define W_DISABLE 0x0000 /* Disable watchdog */
|
|
|
|
/* The scaling factor for the timer, this depends on the value of W_ENABLE */
|
|
#define W_SCALE (32768/1024)
|
|
|
|
static void scx200_wdt_ping(void)
|
|
{
|
|
outw(wdto_restart, scx200_cb_base + SCx200_WDT_WDTO);
|
|
}
|
|
|
|
static void scx200_wdt_update_margin(void)
|
|
{
|
|
printk(KERN_INFO NAME ": timer margin %d seconds\n", margin);
|
|
wdto_restart = margin * W_SCALE;
|
|
}
|
|
|
|
static void scx200_wdt_enable(void)
|
|
{
|
|
printk(KERN_DEBUG NAME ": enabling watchdog timer, wdto_restart = %d\n",
|
|
wdto_restart);
|
|
|
|
outw(0, scx200_cb_base + SCx200_WDT_WDTO);
|
|
outb(SCx200_WDT_WDSTS_WDOVF, scx200_cb_base + SCx200_WDT_WDSTS);
|
|
outw(W_ENABLE, scx200_cb_base + SCx200_WDT_WDCNFG);
|
|
|
|
scx200_wdt_ping();
|
|
}
|
|
|
|
static void scx200_wdt_disable(void)
|
|
{
|
|
printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
|
|
|
|
outw(0, scx200_cb_base + SCx200_WDT_WDTO);
|
|
outb(SCx200_WDT_WDSTS_WDOVF, scx200_cb_base + SCx200_WDT_WDSTS);
|
|
outw(W_DISABLE, scx200_cb_base + SCx200_WDT_WDCNFG);
|
|
}
|
|
|
|
static int scx200_wdt_open(struct inode *inode, struct file *file)
|
|
{
|
|
/* only allow one at a time */
|
|
if (down_trylock(&open_semaphore))
|
|
return -EBUSY;
|
|
scx200_wdt_enable();
|
|
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static int scx200_wdt_release(struct inode *inode, struct file *file)
|
|
{
|
|
if (expect_close != 42) {
|
|
printk(KERN_WARNING NAME ": watchdog device closed unexpectedly, will not disable the watchdog timer\n");
|
|
} else if (!nowayout) {
|
|
scx200_wdt_disable();
|
|
}
|
|
expect_close = 0;
|
|
up(&open_semaphore);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int scx200_wdt_notify_sys(struct notifier_block *this,
|
|
unsigned long code, void *unused)
|
|
{
|
|
if (code == SYS_HALT || code == SYS_POWER_OFF)
|
|
if (!nowayout)
|
|
scx200_wdt_disable();
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block scx200_wdt_notifier =
|
|
{
|
|
.notifier_call = scx200_wdt_notify_sys,
|
|
};
|
|
|
|
static ssize_t scx200_wdt_write(struct file *file, const char __user *data,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
/* check for a magic close character */
|
|
if (len)
|
|
{
|
|
size_t i;
|
|
|
|
scx200_wdt_ping();
|
|
|
|
expect_close = 0;
|
|
for (i = 0; i < len; ++i) {
|
|
char c;
|
|
if (get_user(c, data+i))
|
|
return -EFAULT;
|
|
if (c == 'V')
|
|
expect_close = 42;
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int scx200_wdt_ioctl(struct inode *inode, struct file *file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
void __user *argp = (void __user *)arg;
|
|
int __user *p = argp;
|
|
static struct watchdog_info ident = {
|
|
.identity = "NatSemi SCx200 Watchdog",
|
|
.firmware_version = 1,
|
|
.options = (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING),
|
|
};
|
|
int new_margin;
|
|
|
|
switch (cmd) {
|
|
default:
|
|
return -ENOTTY;
|
|
case WDIOC_GETSUPPORT:
|
|
if(copy_to_user(argp, &ident, sizeof(ident)))
|
|
return -EFAULT;
|
|
return 0;
|
|
case WDIOC_GETSTATUS:
|
|
case WDIOC_GETBOOTSTATUS:
|
|
if (put_user(0, p))
|
|
return -EFAULT;
|
|
return 0;
|
|
case WDIOC_KEEPALIVE:
|
|
scx200_wdt_ping();
|
|
return 0;
|
|
case WDIOC_SETTIMEOUT:
|
|
if (get_user(new_margin, p))
|
|
return -EFAULT;
|
|
if (new_margin < 1)
|
|
return -EINVAL;
|
|
margin = new_margin;
|
|
scx200_wdt_update_margin();
|
|
scx200_wdt_ping();
|
|
case WDIOC_GETTIMEOUT:
|
|
if (put_user(margin, p))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
static const struct file_operations scx200_wdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.write = scx200_wdt_write,
|
|
.ioctl = scx200_wdt_ioctl,
|
|
.open = scx200_wdt_open,
|
|
.release = scx200_wdt_release,
|
|
};
|
|
|
|
static struct miscdevice scx200_wdt_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &scx200_wdt_fops,
|
|
};
|
|
|
|
static int __init scx200_wdt_init(void)
|
|
{
|
|
int r;
|
|
|
|
printk(KERN_DEBUG NAME ": NatSemi SCx200 Watchdog Driver\n");
|
|
|
|
/* check that we have found the configuration block */
|
|
if (!scx200_cb_present())
|
|
return -ENODEV;
|
|
|
|
if (!request_region(scx200_cb_base + SCx200_WDT_OFFSET,
|
|
SCx200_WDT_SIZE,
|
|
"NatSemi SCx200 Watchdog")) {
|
|
printk(KERN_WARNING NAME ": watchdog I/O region busy\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
scx200_wdt_update_margin();
|
|
scx200_wdt_disable();
|
|
|
|
sema_init(&open_semaphore, 1);
|
|
|
|
r = misc_register(&scx200_wdt_miscdev);
|
|
if (r) {
|
|
release_region(scx200_cb_base + SCx200_WDT_OFFSET,
|
|
SCx200_WDT_SIZE);
|
|
return r;
|
|
}
|
|
|
|
r = register_reboot_notifier(&scx200_wdt_notifier);
|
|
if (r) {
|
|
printk(KERN_ERR NAME ": unable to register reboot notifier");
|
|
misc_deregister(&scx200_wdt_miscdev);
|
|
release_region(scx200_cb_base + SCx200_WDT_OFFSET,
|
|
SCx200_WDT_SIZE);
|
|
return r;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit scx200_wdt_cleanup(void)
|
|
{
|
|
unregister_reboot_notifier(&scx200_wdt_notifier);
|
|
misc_deregister(&scx200_wdt_miscdev);
|
|
release_region(scx200_cb_base + SCx200_WDT_OFFSET,
|
|
SCx200_WDT_SIZE);
|
|
}
|
|
|
|
module_init(scx200_wdt_init);
|
|
module_exit(scx200_wdt_cleanup);
|
|
|
|
/*
|
|
Local variables:
|
|
compile-command: "make -k -C ../.. SUBDIRS=drivers/char modules"
|
|
c-basic-offset: 8
|
|
End:
|
|
*/
|